Environment configuration as provided by Symfony is enhanced in eZ Platform to allow specifying this in the virtual host configuration.
You can configure several environments, from production, development or staging, even if for each one of them you need to use different configuration sets.

For example, using Apache, in the VirtualHost example in doc/apache2/ in your install, the required VirtualHost configurations have been already included. You can switch to the desired environment by setting the ENVIRONMENT environment variable to "prod", "dev" or other custom value, as you can see in the following example: